A confiscated Phantasmal poison frog is displayed by the Beijing Entry-Exit Inspection and Quarantine Bureau alongside other prohibited items. YU XIAO/CHINA DAILY

China is the world's biggest e-commerce market, accounting for about 40 percent of the world's online trade. That market is set reach $1 trillion by 2019, according to a report published by Forrester Research, an independent technology monitor.

However, while the growth of online transactions has provided many benefits, it also has many downsides, including one that is exacerbating one of the biggest challenges facing the country's environmental integrity－the rise of invasive alien species.

Every year, non-native species are entering the country in increasing numbers. Some arrive in air and maritime freight, but more and more are being brought into the country illegally via online transactions, causing economic losses and widespread environmental damage by driving native species from their habitats and in some case even wiping them out.

At the last count, there were 544 invasive alien species in China, 50 of which are considered the most dangerous in the world. Their presence results in direct economic losses of 57.4 billion yuan ($8.7 billion) every year.

Tighter regulations

The problem has now become so pressing that new guidelines were enacted on Jan 1, designed to strengthen supervision of cross-border e-commerce. The new rules, which were published by the General Administration of Quality Supervision, Inspection and Quarantine in July, include a series of measures that require inspection and quarantine authorities at all levels to set up files on online stores and build a traceability system for products that pose potential safety risks.

"The introduction of alien species is accelerating. In the past, we only discovered one or two in China every 10 years, but in the past decade, one or two have appeared every year," said Liu Wanxue, a researcher from the Institute of Plant Protection at the Chinese Academy of Agricultural Sciences, in an interview with the Lanzhou Morning Post.

According to data published by the administration, customs officials intercepted and impounded 980,000 harmful aliens from 5,788 different species last year. The inspection and quarantine authorities intercepted overseas deliveries that contained a wide range of alien species, including beetles, scorpions, lizards and snakes. Most had been purchased online by domestic buyers as pets.

In March, the Xiamen Customs spotted four Phantasmal poison frogs in a delivery from Hong Kong. Each frog was capable of producing enough venom to kill 20,000 mice, according to local media reports.

In July, the Nanning Customs in the Guangxi Zhuang autonomous region found 80 cockroaches of six different species that had been bought at an online pet store for about around 8 yuan ($1.22) each.

In November, the customs house in Beijing discovered 992 non-native ants in a delivery of glass test tubes from Germany. The test tubes contained enough syrup and water to ensure the ants survived the journey.

"Alien species are introduced by foreign trade, transportation tools, baggage and mailed items," said Huang Honghui, director of the Animal Inspection and Quarantine Department at the Hainan Entry-Exit Inspection and Quarantine Bureau.

"The rapid development of cross-border e-commerce is increasing the risk of invasion by alien species, and this is putting greater pressure on the inspection process," he said.

Last year, a number of custom houses in China established blacklists containing details of the illegal traffic of alien species and included the names and addresses of senders and recipients. In future, all transactions between the named parties will be subject to increased scrutiny

"The ultimate way to solve the problem is to strengthen publicity of the risks posed by these alien species to raise public awareness," Huang said.

A resident of Qingdao, Shandong province, allows his hercules beetle to crawl on his arm. The huge beetle is native to South America. CHINA DAILY

MA XUEJING/CHINA DAILY

Philanthropic or foolish?

In many cases, the buyers have no idea of the ecological risks posed by their new "pets". If the owners fail to keep them securely locked in cages or tanks, the interlopers can break free, and a lack of predators means their populations grow more rapidly than those of native species, posing a severe threat to the ecosystem.

Not all invasive species arrive through the mail, though. In April, Fiona Sit, a well-known actress and singer from Hong Kong, provoked a storm of online criticism when she "freed", to use her own words, two Brazilian red-eared slider turtles she had bought at a food stall in a market and released them in the Bride's Pool, a stream with several waterfalls in the New Territories of Hong Kong.

When the 25-year-old posted photos of the turtles on her micro blog, she was inundated with comments from concerned netizens who pointed out the negative ecological impact the turtles would have on the local eco-system because of their lower age of maturity, higher rates of reproduction and larger body size, all of which give them competitive advantages compared with native species. The turtles are also banned in many countries because they are known to transmit a range of diseases.

"It's not uncommon for people to take Brazilian sliders to release them into lakes. They may see this as a philanthropic act, but what they don't realize is that these turtles are highly adaptable, rapidly reproducing predators," said Li Yiming, a researcher into animal ecology at the Institute of Zoology with the Chinese Academy of Sciences.

A customs officer displays ants found in test tubes imported from Germany in November. HUANG HAIPENG/CHINA DAILY

Red for danger

Southern China is also experiencing an infestation of red imported fire ants, a highly aggressive, toxic species that can destroy habitats. The insect's bite causes severe pain and skin blisters, and can even cause unconsciousness in people who are particularly susceptible to the venom.

The ants, which are native to South America, are predominantly found in southern China. They were first spotted in Taiwan about 15 years ago, and are thought to have arrived via cargo containers and soil used for ballast in ships.

They later arrived on the mainland via ships that docked at ports in the coastal province of Guangdong, and now the story is being played out again in the tourist haven of Hainan Island, China's southernmost province, where they are harming the local eco-system and posing a threat to public health.

The ants are highly aggressive and territorial. Wang Chunqiong, from Ding'an county in Hainan, has scars on her arms and legs after an encounter with the ants. "They usually hide in dry places in the crop fields, waiting for a chance to bite you when you are not looking. Almost everybody in the village has been bitten," the 65-five-year-old said.

The small, fast-moving insects sting their victims repeatedly, and are especially dangerous to the young and newborn babies.

In addition to the dangers they pose to humans and animals life, they are voracious, eating the buds and fruits of numerous crops, especially corn, soybeans, okra and citrus fruits. "They have eaten all our peanuts, but they are also destroying other crops and hampering agricultural production. We wish we could get rid of them," Wang said.

Her wish is easier said than done, though. When an alien species enter the natural environment, the creatures usually assume a place at the top of the food chain, and lacking predators, their numbers grow rapidly.

"The ecological hazards caused by invasive alien species include the eradication of certain local species, reducing biological diversity, polluting soil and water, and transmitting infectious diseases," said Li, from the CAS. "Once the population of an invasive species is established, it is very difficult to eliminate them completely. Even the most feasible methods－catching or killing them by hand－are too expensive."

Contact the writers at chengyingqi@chinadaily.com.cn and liuxiaoli@chinadaily.com.cn